1. Technical Field
The present invention relates to image processing apparatus or methods, such as an image generating apparatus to generate an image and an image reading apparatus to read such an image. In particular, the present invention relates to a technique for generating coordinate-addressed, tagged images, in which the position within an image can be obtained by reading machine-readable codes embedded in the background or the like of the image, and a technique for reading such coordinate-addressed, tagged images.
2. Related Art
A new user interface technique has been proposed in which, for example, coordinate address information is embedded beforehand in a paper page so that the position of a point on the page can be identified, which enables access to electronic information associated with a coordinate address on the page by reading the coordinate address information.
However, when location information on paper pages is represented by a two-dimensional code, the use of a larger two-dimensional code increases the location information that can be represented, whereas the distance between the intervals at which location can be represented increases. Consequently, the image capturing area of a scanner such as a charge-coupled device (CCD) installed on a pen has to be made larger or a higher density image capturing element with a brighter optical device for delivering a higher resolution has to be used. This has posed the following problems: the pen size has to be made greater, the optical device of the pen is costly, and the system cost increases. Conversely, when a smaller two-dimensional code is used, these problems do not occur. However, the amount of information that can be embedded in a two-dimensional code decreases. Thus, the coordinate address information (address space) that can be represented decreases, the number of sheets in which coordinates can be addressed and issued decreases, and eventually address depletion will take place. To avoid this, if duplicated coordinate addresses are used, it becomes difficult to trace information on a paper page scanned by the pen, for example, by locating the information in what page of what document.